In fact, a new study of 12 representative megachurches spread across the country finds that the size of these churches is a major part of their appeal. Members report that the experience of worshiping with thousands is intoxicating, the researchers find.

"It's an addicting experience, it's so large, it's so huge," said study researcher Katie Corcoran, a graduate student in sociology at the University of Washington. "One respondent said you can look up to the balcony and see the Holy Spirit go over the crowd like a wave in a football game."

Prior research had suggested that megachurches were rather soulless — entertaining, but lacking a sense of spirituality or belonging, Corcoran told LiveScience.

"We went in thinking that’s what we were going to find," she said. "Instead, we actually found the opposite, that people do experience strong feelings of belonging. They're very happy with their megachurch, and the size is actually seen as a positive rather than a negative." [8 Ways Religion Impacts Your Life]